In controlling the transmission of fluids in oil and natural gas (CH4) pipeline distribution systems, in chemical processing systems, and the like, it is often necessary to transmit the fluid at a relatively high pressure through portions of the distribution system. As the high pressure fluid travels through the distribution system, the pressure of the fluid may be reduced, typically to a controlled or selected pressure setting, at one or more points to supply the fluid at a lower pressure to a subsystem that uses or consumes the fluid.
Pilot-operated pressure regulators or flow control valves are used for pressure control and/or adjustment and/or back pressure relief and/or differential pressure and/or flow rate control applications, such as to regulate the flow of a fluid, such as natural gas, in a conduit, such as a pipeline. That is, such devices allow for controlling and/or adjusting fluid pressure and/or adjusting fluid flow between an upstream portion of the conduit and a downstream portion of the conduit.
U.S. Pat. No. 6,173,735, incorporated herein by reference in its entirety, discloses a valve having multiple throttle plates. However, among its characteristics, the valve of the '735 patent uses multiple throttle plates that are individually bolted to the valve body and are not stacked. In addition, the concentric rows of apertures within the throttle plates overlap and are not set apart by row dividers. As will be apparent from further discussion hereinafter, there are other differences that exist between the valve of the '735 patent and embodiments of the one or more present inventions.
There is a need for additional devices for adjusting and/or controlling the pressure and/or flow of fluid in a conduit to provide a relatively smooth pressure change between the upstream and downstream portions of the conduit after a pressure change and/or flow rate in at least one of the upstream or downstream portions.
In addition, present valves typically generate considerable noise as the fluid flows through them, often requiring multiple valves to be used in series to control or adjust any pressure changes in smaller, incremental steps, or other methods to reduce the noise generated. Thus, there is a need for devices or valves capable of adjusting and/or controlling the flow of fluid in a conduit at reduced noise and/or decibel levels for a given change in pressure and/or flow rate.